LEPL is a recursive descent parser library written
in Python. It is based on parser combinator
libraries popular in functional programming, but
also exploits Python language features. Operators
provide a friendly syntax, and the consistent use
of generators supports full backtracking and
resource management. Backtracking implies that a
wide variety of grammars are supported; appropriate memoisation ensures that even left-recursive grammars terminate.

HabuL is a Thunderbird addon that reports spam to the SpamCop, the FTC, FDA, SEC, ACMA, and Knujon.com. It also allows you to put in your own custom addresses to report spam to such parties as your ISP or corporate abuse address.

RXPY is a pure-Python regular expression library, compatible with the re package. RXPY can be used as a test-bed for new matching algorithms, since the parser and compatibility components are reusable.

osashosa is a Dependency Injection Framework styled after Guice. It is actually a drop in replacement for a large subset of Guice 2.0. Its main use is for library developers. Instead of asking users to include a 500k dependency, they can choose to use a 24k dependency instead.

Candle App Platform is an XML-centric rich application development platform for both desktops and the Internet. It supports technologies like XSLT, XQuery, XML Scheme, XUpdate, XHTML, and SVG, and a new scripting language - Candle (Common ApplicatioN Development LanguagE).